Cold planers, sometimes also called road mills, scarifiers, or surface treatment machines, rotate a drum with cutting bits over a work surface. These machines are designed to prepare or treat a surface like a road, pavement, or soil. A motor connected to the drum by way of a drive train and gearbox rotates the drum so that the cutting bits alter the work surface. The cold planer also includes a conveyor system that generally has a primary conveyor that receives debris cut by the drum and transfers the debris to a secondary conveyor. The secondary conveyor then transports the debris away from the machine to a truck for removal.
Conveyor belts of the conveyor system are monitored by a worker or cold planer operator. As work load on the belts increases, tension on the belts similarly increases. The worker or operator observes the belt and when a problem is noticed such as a lose belt or a mis-tracked belt, tension on the belt is adjusted by repositioning the end roller of a conveyor. Often operators of cold planers use hand tools to mechanically adjust the tension in the conveyor system. This is typically performed with a threaded rod connected to the support bearings for the head pulleys of the conveyor belt. When the belt is in need of adjustment, the operators use hand tools to manually adjust the tension of both sides of the belt until it is tensioned and tracking correctly. In many cases, operators perform these adjustments with the belts running as it is necessary for the belt to rotate in order for the adjustments to take effect. Not only is this not user friendly, user error can result in undesired over-tensioning on the belts leading to belt wear, reduced belt life, reduced lift of conveyor components such as bearings, rollers and pulleys, and inefficient performance of the conveyor.
Other conveyor belt systems utilize a controller. Chinese Pat. No. CN206705106U to Yinghua presents a conveyor belt tension adjusting machine. The machine has dual clutch piston cylinders and pressure sensors. A PLC controller is provided to dynamically adjust the belt tension to maintain a symmetrical arrangement of two cylinders during operation.
Still, conveyor belt tensioning systems remain susceptible to wear, over-tensioning, and reduced life. Difficulties in use and maintenance also persist.